Yup. I contacted him thru his KLR Chris contact page, and we emailed back and forth a bit, then had a 20 minute chat on the phone. Very helpful - I was very impressed by the guy, his knowledge, helpfulness, etc. I did some Googling, found posts in Subaru tuning forums heaping praise on him and his speed shop.When I talked to Chris he is pretty much fed up with arguing with people. If you send private messages he will answer best he can. He was in engine building racket for a long time and just laying low now enjoying life. Was a great guy to talk to. Very knowledgeable.
It would be good to be able to dyno it, be able to verify the change, confirm whether it makes additional power. Ideal is to make only one change at a time, check the results. Even without a dyno, full throttle roll on testing, from 50 to 70 miles per hour for example, carefully timed using GPS, and recorded (video) could produce meaningful data in lieu of dyno testing.Hmm, you guy have given me some interesting reading. If you recall I had Web Cams build me set of higher lift/duration cams from a low mileage 2018 set I bought. It has the KACR installed plus I bought the heavy duty spring set with titanium retainers for it too. KLRChris & his friend have them now along with the head assembly for a quad port setup.
It’s going to be interesting to see how it all works out.
GWN. You hoser.It would be good to be able to dyno it, be able to verify the change, confirm whether it makes additional power. Ideal is to make only one change at a time, check the results. Even without a dyno, full throttle roll on testing, from 50 to 70 miles per hour for example, carefully timed using GPS, and recorded (video) could produce meaningful data in lieu of dyno testing.
I put the head aside, calling that one done. The small amount of leakage is somewhat normal methinks. Let 'em sit there long enough, with a very thin fluid (I've used penetrating oil before), you're bound to get a little leakage methinks. To my way of thinking, those valves will bed in quickly, clearances tightening up a tad. In the big picture, this head refurbishment is about extending the life, and restoring performance (compression).GWN are you gaining ground on project?Im just tearing mine down.
Are you disassembling the head? Record the clearances & shim sizes before you do.I ended up getting everything tore down yesterday. Cylinder and sleeve off. Minimal wear on piston and sleeve. There is quite abit of carbon build up on head and piston which looks like engine running plenty rich. Maybe using some oil. Looks to me that oil coming from valve seals as no tell tale signs on piston.
That's pretty good, exhaust valves haven't recessed all that far, roughly .004" more than the intakes. They were likely all around 275, maybe even 280 to start with. What year is your bike? Maybe post up a pic of the wear on the seats?Gwn i checked shims on intake they are 275 and 265 on exh. Unfortunately i did not check clearance before i took apart.
Just wanted you to know that over three years later I am really appreciating your wealth of knowledge, willingness to share, and the time and effort you put into making these posts. Thank you! 🙏I thought maybe I could contribute some useful information regarding refreshing a head. I've had (I think) 6 heads apart, Gen 1 & Gen 2, have seen some pretty bad valve & valve seat wear, on engines that didn't have particularly high mileage on 'em. You can get a pretty good idea of how much valve & valve seat wear an engine has, by the shims required to get valve lash in spec. Each shim increment of adjustment, equates to approximately .002" the valve has recessed (worn) deeper into the head. Worn valves & valve seats affects compression (performance). So often I see guys addressing high oil consumption, replace the piston & rings, but don't refresh the head, only doing 1/2 the job IMO - most mid to high mileage engines could benefit from de-carboning, and at least lapping the valves to restore compression. The Eagle Mike head refurbishment program, at $190 USD, is a bargain IMO.
This is a head from an '01 Gen 1 that I took in trade (set a friend up with a 685 I built), and I think it had around 50,000 miles/80,000 kms (was a bad oil burner). This is, unfortunately, usually the condition I find heads in when I disassemble 'em.
The max width, as per the factory manual, for the valve contact patch on the valve seat, is 1.2mm, both intake and exhaust. The intakes are at max, and exhaust over 2mm. The valve seats are badly pitted, especially exhaust. This head requires valve seat regrinding, and two new exhaust valves.
Here's a few tools of the trade. I'll illustrate/document the process as I progress (if there's interest).
Thanks! I really enjoyed porting those heads. It's a lot of work, takes quite a bit of time to do, but very satisfying. Hopefully this thread inspires other to do likewise.Just wanted you to know that over three years later I am really appreciating your wealth of knowledge, willingness to share, and the time and effort you put into making these posts. Thank you! 🙏
Thanks for the great postings. It's so helpful to see what the challenges are. Did you do a section on what tool bits were used on what and what to watch out for?Here's a finished intake port from a head I did a while back:
And an exhaust port:
I'll get to working on this head, see if I can get some better pics, post 'em up as I go. I hope a few people find this helpful/valuable.